Methods and apparatus for taking spectroscopic measurements of sediment

Abstract

A spectrometer system includes a processing center, an underwater remote sensor and a communication link coupled therebetween. The sensor is deployed to at least partially penetrate a sediment layer disposed beneath a body of water. The sensor includes a window defining a sediment window plane through which a profile of the sediment layer is observable and a camera, an image plane of which is a conjugate of the window, the camera imaging light from objects in the sediment window plane to generate imagewise data, the imagewise data being transmitted over the communications link to the processing center. The sensor also includes at least one removable cell disposed in the sediment window plane, each removable cell being comprised of a transparent solid material having a void therein, the void in each removable cell for holding a standard material corresponding to the respective removable cell. The sensor further includes a camera filter device having at least one camera filter. Each camera filter is characterized as passing radiant energy within a corresponding emission band of camera wavelengths, the camera filter device being controllable to select a current camera filter. The sensor further includes an illumination source to produce radiant energy and an illumination filter device having at least one illumination filter. Each illumination filter is characterized as passing radiant energy within a corresponding illumination band of wavelengths. The sensor further includes a blocking filter device having at least one blocking filter, each blocking filter being synchronously coordinated with a corresponding illumination filter to block light in the illumination band from reaching the camera.